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Water-associated nosocomial infections.
yesIt is estimated that 5-10% of hospitalised patients in
developed countries contract hospital acquired infections
(HAI). Increasing levels of antimicrobial resistance manifested
by many HAI-causing pathogens such as Acinetobacter spp in
the intensive care unit (ICU) setting present a significant
challenge to those managing these infections. Consequently,
much attention has been focused on the prevention of HAIs.
Particular emphasis has been placed on interventions
intended to interrupt patient-to-patient transmission of pathogens,
such as enhanced hand hygiene and identification of
patients colonised with methicillin-resistant Staphylococcus
aureus (MRSA) using rapid DNA-based screening techniques.
However, comparatively little attention has been given to the
hospital environment, including water supplies, as a source of
nosocomial pathogens of importance for patients on the
critical care unit. This article reviews the role of hospital water
sources in the epidemiology of HAI and new technologies
which can be employed in the prevention and control of such
infections
Current and future applications of GnRH, kisspeptin and neurokinin B analogues
Reproductive hormones affect all stages of life from gamete production, fertilization, fetal development and parturition, neonatal development and puberty through to adulthood and senescence. The reproductive hormone cascade has, therefore, been the target for the development of numerous drugs that modulate its activity at many levels. As the central regulator of the cascade, gonadotropin-releasing hormone (GnRH) agonists and antagonists have found extensive applications in treating a wide range of hormone-dependent diseases, such as precocious puberty, prostate cancer, benign prostatic hyperplasia, endometriosis and uterine fibroids, as well as being an essential component of in vitro fertilization protocols. The neuroendocrine peptides that regulate GnRH neurons, kisspeptin and neurokinin B, have also been identified as therapeutic targets, and novel agonists and antagonists are being developed as modulators of the cascade upstream of GnRH. Here, we review the development and applications of analogues of the major neuroendocrine peptide regulators of the reproductive hormone cascade: GnRH, kisspeptin and neurokinin B.The Medical Research Council (South Africa), the National Research Foundation, the University of Pretoria and the University of Cape Town. CLN is a Claude Leon Foundation Postdoctoral Research Fellow.http://www.nature.com/nrendohb2016Mammal Research InstituteZoology and Entomolog
Lack of oestrogen receptor expression in breast cancer cells does not correlate with kisspeptin signalling and migration
DATA AVAILABILITY STATEMENT : All data recorded in this study is archived online within Benchling.com
and is available upon request to the corresponding author.Kisspeptin is an anti-metastatic mediator in many cancer types, acting through its receptor,
KISS1R. However, controversy remains regarding its role in breast cancer since both pro- and antimetastatic roles have been ascribed to it. In KISS1R overexpressing triple-negative breast cancer
(TNBC) cells, stimulation has been associated with increased invasion and MMP-9 expression, leading
to the suggestion that hormone receptor status determines the metastatic effects of kisspeptin. To
assess the veracity of this claim, we compared endogenous KISS1R signalling and physiological
output in the hormone receptor-negative MDA-MB-231 and BT-20 cell lines after KP-10 (shortest
active kisspeptin peptide) stimulation. MDA-MB-231 cells are metastatic when implanted in mice
while BT-20 are not and remain epithelial-like. We show that both cell lines express KISS1R mRNA
and respond to KP-10 by elevating calcium mobilisation. However, KP-10 stimulation induced
migration of MDA-MB-231, but not BT-20 cells, in a calcium-dependent manner. Moreover, only
BT-20 cells responded to KP-10 by increasing ERK phosphorylation in a β-arrestin-dependent manner.
Interestingly, both cell lines displayed different complements of β-arrestin 1 and 2 expression. Overall,
our data shows that, in TNBC, it is not universally true that kisspeptin/KISS1R stimulate migration
or pro-metastatic behaviour, as divergent responses were observed in the two TNBC lines tested.
Whether this divergence is related to the observed differences in β-arrestin complements warrants
further investigation and may enable further stratification of the ability of kisspeptin to influence
breast tumour behaviour.The National Research Foundation, South Africa and SGKN Trust.https://www.mdpi.com/journal/ijerphImmunologyPhysiolog
The Brugia malayi neuropeptide receptor-4 is activated by FMRFamide-like peptides and signals via Gα
Genetic studies undertaken in the model organism Caenorhabditis elegans have demonstrated the importance
of neuropeptidergic signalling in nematode physiology. Disruption of this signalling may have
deleterious phenotypic consequences, including altered locomotion, feeding behaviour, and reproduction.
Neuropeptide G protein-coupled receptors (GPCRs) that transduce many of these signals therefore
represent cogent drug targets. Recently published genomic sequencing data for a number of parasitic
helminths of medical and veterinary importance has revealed the apparent conservation of a number of
neuropeptides, and neuropeptide receptors between parasitic and free-living species, raising the intriguing
possibility of developing broad-spectrum anthelmintic therapeutics. Here, we identify and clone a
neuropeptide receptor, NPR-4, from the human filarial nematode Brugia malayi and demonstrate its activation
in vitro, by FMRFamide-like peptides of the FLP-18 family, and intracellular signalling via G i
mediated pathways. These data represent the first example of deorphanisation of a neuropeptide GPCR
in any parasitic helminth species.MRC South Africa and the University of Cape Town.http://www.journals.elsevier.com/molecular-and-biochemical-parasitology/hb2014Zoology and EntomologyMammal Research Institut
Loss-of-function mutations in the human luteinizing hormone receptor predominantly cause intracellular retention
This work was supported by the South African Medical Research
Council (Award to the MRC/UCT Receptor Biology
Research Unit); the Claude Leon Foundation, South Africa (Postdoctoral
Research Fellowship: C.L.N.); the University of Cape
Town (URC Fellowship: R.C.A.); The University of Pretoria
(RDP grants: C.L.N. and R.C.A.); and the National Research
Foundation, South Africa (CSUR Grant [94008]: C.L.N.).http://press.endocrine.org/journal/endoam2016ImmunologyPhysiologyZoology and Entomolog
Rescue of cell surface expression and signaling of mutant follicle-stimulating hormone receptors
Mutations in G protein-coupled receptors (GPCRs) underlie numerous diseases. Many cause receptor misfolding and failure to reach the cell surface. Pharmacological chaperones are cell-permeant small molecules that engage nascent mutant GPCRs in the endoplasmic reticulum, stabilizing folding and "rescuing" cell surface expression. We previously demonstrated rescue of cell surface expression of luteinizing hormone receptor mutants by an allosteric agonist. Here we demonstrate that a similar approach can be employed to rescue mutant follicle-stimulating hormone receptors (FSHRs) with poor cell surface expression using a small-molecule FSHR agonist, CAN1404. Seventeen FSHR mutations described in patients with reproductive dysfunction were expressed in HEK 293T cells, and cell surface expression was determined by enzyme-linked immunosorbent assay of epitope-tagged FSHRs before/after treatment with CAN1404. Cell surface expression was severely reduced to ≤18% of wild-type (WT) for 11, modestly reduced to 66% to 84% of WT for 4, and not reduced for 2. Of the 11 with severely reduced cell surface expression, restoration to ≥57% of WT levels was achieved for 6 by treatment with 1 µM CAN1404 for 24 h, and a corresponding increase in FSH-induced signaling was observed for 4 of these, indicating restored functionality. Therefore, CAN1404 acts as a pharmacological chaperone and can rescue cell surface expression and function of certain mutant FSHRs with severely reduced cell surface expression. These findings aid in advancing the understanding of the effects of genetic mutations on GPCR function and provide a proof of therapeutic principle for FSHR pharmacological chaperones.https://academic.oup.com/endohj2022ImmunologyPhysiolog
Characteristics of outdoor falls among older people: A qualitative study
Background Falls are a major threat to older people’s health and wellbeing. Approximately half of falls occur in outdoor environments but little is known about the circumstances in which they occur. We conducted a qualitative study to explore older people’s experiences of outdoor falls to develop understanding of how they may be prevented. Methods We conducted nine focus groups across the UK (England, Wales, and Scotland). Our sample was from urban and rural settings and different environmental landscapes. Participants were aged 65+ and had at least one outdoor fall in the past year. We analysed the data using framework and content analyses. Results Forty-four adults aged 65 – 92 took part and reported their experience of 88 outdoor falls. Outdoor falls occurred in a variety of contexts, though reports suggested the following scenarios may have been more frequent: when crossing a road, in a familiar area, when bystanders were around, and with an unreported or unknown attribution. Most frequently, falls resulted in either minor or moderate injury, feeling embarrassed at the time of the fall, and anxiety about falling again. Ten falls resulted in fracture, but no strong pattern emerged in regard to the contexts of these falls. Anxiety about falling again appeared more prevalent among those that fell in urban settings and who made more visits into their neighbourhood in a typical week. Conclusions This exploratory study has highlighted several aspects of the outdoor environment that may represent risk factors for outdoor falls and associated fear of falling. Health professionals are recommended to consider outdoor environments as well as the home setting when working to prevent falls and increase mobility among older people
Identifying molecular mediators of the relationship between body mass index and endometrial cancer risk:a Mendelian randomization analysis
Endometrial cancer is the most common gynaecological cancer in high-income countries. Elevated body mass index (BMI) is an established modifiable risk factor for this condition and is estimated to confer a larger effect on endometrial cancer risk than any other cancer site. However, the molecular mechanisms underpinning this association remain unclear. We used Mendelian randomization (MR) to evaluate the causal role of 14 molecular risk factors (hormonal, metabolic and inflammatory markers) in endometrial cancer risk. We then evaluated and quantified the potential mediating role of these molecular traits in the relationship between BMI and endometrial cancer using multivariable MR.
Methods
Genetic instruments to proxy 14 molecular risk factors and BMI were constructed by identifying single-nucleotide polymorphisms (SNPs) reliably associated (P < 5.0 × 10−8) with each respective risk factor in previous genome-wide association studies (GWAS). Summary statistics for the association of these SNPs with overall and subtype-specific endometrial cancer risk (12,906 cases and 108,979 controls) were obtained from a GWAS meta-analysis of the Endometrial Cancer Association Consortium (ECAC), Epidemiology of Endometrial Cancer Consortium (E2C2) and UK Biobank. SNPs were combined into multi-allelic models and odds ratios (ORs) and 95% confidence intervals (95% CIs) were generated using inverse-variance weighted random-effects models. The mediating roles of the molecular risk factors in the relationship between BMI and endometrial cancer were then estimated using multivariable MR
Are Ethnic and Gender Specific Equations Needed to Derive Fat Free Mass from Bioelectrical Impedance in Children of South Asian, Black African-Caribbean and White European Origin? Results of the Assessment of Body Composition in Children Study
Background
Bioelectrical impedance analysis (BIA) is a potentially valuable method for assessing lean mass and body fat levels in children from different ethnic groups. We examined the need for ethnic- and gender-specific equations for estimating fat free mass (FFM) from BIA in children from different ethnic groups and examined their effects on the assessment of ethnic differences in body fat.
Methods
Cross-sectional study of children aged 8–10 years in London Primary schools including 325 South Asians, 250 black African-Caribbeans and 289 white Europeans with measurements of height, weight and arm-leg impedance (Z; Bodystat 1500). Total body water was estimated from deuterium dilution and converted to FFM. Multilevel models were used to derive three types of equation {A: FFM = linear combination(height+weight+Z); B: FFM = linear combination(height2/Z); C: FFM = linear combination(height2/Z+weight)}.
Results
Ethnicity and gender were important predictors of FFM and improved model fit in all equations. The models of best fit were ethnicity and gender specific versions of equation A, followed by equation C; these provided accurate assessments of ethnic differences in FFM and FM. In contrast, the use of generic equations led to underestimation of both the negative South Asian-white European FFM difference and the positive black African-Caribbean-white European FFM difference (by 0.53 kg and by 0.73 kg respectively for equation A). The use of generic equations underestimated the positive South Asian-white European difference in fat mass (FM) and overestimated the positive black African-Caribbean-white European difference in FM (by 4.7% and 10.1% respectively for equation A). Consistent results were observed when the equations were applied to a large external data set.
Conclusions
Ethnic- and gender-specific equations for predicting FFM from BIA provide better estimates of ethnic differences in FFM and FM in children, while generic equations can misrepresent these ethnic differences
Birthweight and risk markers for type 2 diabetes and cardiovascular disease in childhood: the Child Heart and Health Study in England (CHASE).
AIMS/HYPOTHESIS: Lower birthweight (a marker of fetal undernutrition) is associated with higher risks of type 2 diabetes and cardiovascular disease (CVD) and could explain ethnic differences in these diseases. We examined associations between birthweight and risk markers for diabetes and CVD in UK-resident white European, South Asian and black African-Caribbean children.
METHODS: In a cross-sectional study of risk markers for diabetes and CVD in 9- to 10-year-old children of different ethnic origins, birthweight was obtained from health records and/or parental recall. Associations between birthweight and risk markers were estimated using multilevel linear regression to account for clustering in children from the same school.
RESULTS: Key data were available for 3,744 (66%) singleton study participants. In analyses adjusted for age, sex and ethnicity, birthweight was inversely associated with serum urate and positively associated with systolic BP. After additional height adjustment, lower birthweight (per 100 g) was associated with higher serum urate (0.52%; 95% CI 0.38, 0.66), fasting serum insulin (0.41%; 95% CI 0.08, 0.74), HbA1c (0.04%; 95% CI 0.00, 0.08), plasma glucose (0.06%; 95% CI 0.02, 0.10) and serum triacylglycerol (0.30%; 95% CI 0.09, 0.51) but not with BP or blood cholesterol. Birthweight was lower among children of South Asian (231 g lower; 95% CI 183, 280) and black African-Caribbean origin (81 g lower; 95% CI 30, 132). However, adjustment for birthweight had no effect on ethnic differences in risk markers.
CONCLUSIONS/INTERPRETATION: Birthweight was inversely associated with urate and with insulin and glycaemia after adjustment for current height. Lower birthweight does not appear to explain emerging ethnic difference in risk markers for diabetes
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